1243941917 has 2 divisors, whose sum is σ = 1243941918. Its totient is φ = 1243941916.

The previous prime is 1243941911. The next prime is 1243941931. The reversal of 1243941917 is 7191493421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1233835876 + 10106041 = 35126^2 + 3179^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1243941917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1243941911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621970958 + 621970959.

It is an arithmetic number, because the mean of its divisors is an integer number (621970959).

Almost surely, 2^1243941917 is an apocalyptic number.

It is an amenable number.

1243941917 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243941917 is an equidigital number, since it uses as much as digits as its factorization.

1243941917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 41.

The square root of 1243941917 is about 35269.5607712940. The cubic root of 1243941917 is about 1075.4742935397.

The spelling of 1243941917 in words is "one billion, two hundred forty-three million, nine hundred forty-one thousand, nine hundred seventeen".